def _calc_pop_fracs(n_dim, phases, sample_rng_seeds, max_int):
# compute volume of each phase
vol_rng = sample_rng_seeds['fraction']
n_phases = len(phases)
rel_vols = np.ones(n_phases)
for i, phase in enumerate(phases):
vol = phase.get('fraction', 1)
try:
v_sample = -1
while v_sample < 0:
v_sample = vol.rvs(random_state=vol_rng)
vol_rng = (vol_rng + 1) % max_int
rel_vols[i] = v_sample
except AttributeError:
rel_vols[i] = vol
vol_fracs = rel_vols / sum(rel_vols)
# Compute the average grain volume of each phase
if n_dim == 2:
avg_vols = [
geometry.factory(p['shape']).area_expectation(**p) for p in phases
]
else:
avg_vols = [
geometry.factory(p['shape']).volume_expectation(**p)
for p in phases
]
weights = vol_fracs / np.array(avg_vols)
pop_fracs = weights / sum(weights)
return pop_fracs
def _get_n_dim(phases):
n_dim = None
for phase in phases:
if 'shape' in phase:
n_dim = geometry.factory(phase['shape']).n_dim
if n_dim is None:
e_str = 'Number of dimensions could not be determined from phase '
e_str += 'shapes. Consider setting the shape of a phase, or'
e_str += ' specifying the number of dimensions.'
raise ValueError(e_str)
return n_dim
def read_input(filename):
"""Convert input file to dictionary
This function reads an input file and parses it into a dictionary.
Args:
filename (str): The name of an XML input file.
Returns:
collections.OrderedDict: Dictionary of run inputs.
"""
# Read in the file
file_path = os.path.dirname(filename)
with open(filename, 'r') as file:
file_dict = xmltodict.parse(file.read())
assert 'input' in file_dict, 'Root <input> not found in input file.'
in_data = dict_convert(file_dict['input'], file_path)
k_args = ('material', 'domain')
for arg in k_args:
assert arg in in_data
# Get domain
domain_data = in_data['domain']
domain_shape = domain_data['shape']
domain_kwargs = {k: v for k, v in domain_data.items() if k != 'shape'}
domain = geometry.factory(domain_shape, **domain_kwargs)
in_data['domain'] = domain
# Default settings
kwargs = in_data.get('settings', {})
run_dir = kwargs.get('directory', '.')
if not os.path.isabs(run_dir):
rel_path = os.path.join(file_path, run_dir)
kwargs['directory'] = os.path.expanduser(os.path.normpath(rel_path))
in_data['settings'] = kwargs
return in_data
def factory(cls, seed_type, phase=0, breakdown=None, position=None,
**kwargs):
"""Factory method for seeds
This function returns a seed based on the seed type and keyword
arguments associated with that type. The currently supported types
are:
* circle
* ellipse
* ellipsoid
* rectangle
* sphere
* square
If the seed_type is not on this list, an error is thrown.
Args:
seed_type (str): type of seed, from list above.
phase (int): *(optional)* Material phase number of seed.
Defaults to 0.
breakdown (list or numpy.ndarray): *(optional)* List of circles or
spheres that approximate the geometry. The list should be
formatted as follows::
breakdown = [(x1, y1, z1, r1),
(x2, y2, z2, r2),
...]
The breakdown will be automatically generated if not provided.
position (list or numpy.ndarray): *(optional)* The coordinates of
the seed. Default is the origin.
**kwargs: Keyword arguments that define the size, shape, etc of the
seed geometry.
Returns:
Seed: An instance of the class.
"""
assert type(seed_type) is str
seed_type = seed_type.strip().lower()
if seed_type == 'nonetype':
n_dim = 0
else:
n_dim = geometry.factory(seed_type).n_dim
if 'volume' in kwargs:
if n_dim == 2:
size = 2 * np.sqrt(kwargs['volume'] / np.pi)
else:
size = 2 * np.cbrt(3 * kwargs['volume'] / (4 * np.pi))
kwargs['size'] = size
# Catch NoneType geometries
if seed_type == 'nonetype':
geom = None
else:
geom = geometry.factory(seed_type, **kwargs)
if breakdown is None:
if seed_type in ('circle', 'sphere'):
breakdown = np.append(geom.center, geom.r).reshape(1, -1)
else:
breakdown = geom.approximate()
if position is None:
position = [0 for _ in range(geom.n_dim)]
return cls(geom, phase, breakdown, position)
def from_info(cls, phases, volume, rng_seeds={}):
"""Create seed list from microstructure information
This function creates a seed list from information about the
microstruture. The "phases" input should be a list of material
phase dictionaries, formatted according to the :ref:`phase_dict_guide`
guide.
The "volume" input is the minimum volume of the list of seeds. Seeds
will be added to the list until this volume threshold is crossed.
Finally, the "rng_seeds" input is a dictionary of random number
generator (RNG) seeds for each parameter of the seed geometries.
For example, if one of the phases uses "size" to define the seeds,
then "size" could be a keyword of the "rng_seeds" input. The value
should be a non-negative integer, to seed the RNG for size.
The default RNG seed is 0.
Note:
If two or more parameters have the same RNG seed and the same
kernel of the distribution, those parameters will **not** be
correlated. This method updates RNG seeds based on the order that
distributions are sampled to avoid correlation between independent
random variables.
Args:
phases (dict): Dictionary of phase information, see
:ref:`phase_dict_guide` for a guide.
volume (float): The total area/volume of the seeds in the list.
rng_seeds (dict): *(optional)* Dictionary of RNG seeds for each
step in the seeding process. The dictionary keys should match
shape parameters in ``phases``. For example::
rng_seeds = {
'size': 0,
'angle': 3,
}
Returns:
SeedList: An instance of the class containing seeds prescribed by
the phase information and filling the given volume.
"""
# determine dimensionality, set default shape
default_shapes = {2: 'circle', 3: 'sphere'}
n_dim = None
if isinstance(phases, dict):
phases = [phases]
for phase in phases:
if 'shape' in phase:
n_dim = geometry.factory(phase['shape']).n_dim
if n_dim is None:
e_str = 'Number of dimensions could not be determined from phase '
e_str += 'shapes. Consider setting the shape of a phase, or'
e_str += ' specifying the number of dimensions.'
raise ValueError(e_str)
for phase in phases:
if 'shape' in phase:
assert geometry.factory(phase['shape']).n_dim == n_dim
else:
phase['shape'] = default_shapes[n_dim]
# compute volume of each phase
vol_rng = rng_seeds.get('fraction', 0)
np.random.seed(vol_rng)
n_phases = len(phases)
rel_vols = np.ones(n_phases)
for i, phase in enumerate(phases):
vol = phase.get('fraction', 1)
try:
v_sample = -1
while v_sample < 0:
v_sample = vol.rvs()
rel_vols[i] = v_sample
except AttributeError:
rel_vols[i] = vol
vol_fracs = rel_vols / sum(rel_vols)
phase_vols = volume * vol_fracs
# compute number of seeds for each phase
if n_dim == 2:
avg_vols = [
geometry.factory(p['shape']).area_expectation(**p)
for p in phases
]
else:
avg_vols = [
geometry.factory(p['shape']).volume_expectation(**p)
for p in phases
]
weights = phase_vols / np.array(avg_vols)
pop_fracs = weights / sum(weights)
seed_vol = 0
seeds = []
max_int = np.iinfo(np.int32).max
while seed_vol < volume:
# Pick the phase
rng_seed = rng_seeds.get('phase', 0)
np.random.seed(rng_seed)
phase_num = np.random.choice(n_phases, p=pop_fracs)
phase = phases[phase_num]
rng_seeds['phase'] = np.random.randint(max_int)
# Create the seed
seed_shape = phase['shape']
seed_args = {'phase': phase_num}
kw_n = 0
for kw in set(phase) - set(_misc.gen_kws):
# set the RNG seed
rng_seed = rng_seeds.get(kw, 0)
np.random.seed(rng_seed)
# Sample, with special cases for orientation
if kw not in _misc.ori_kws:
try:
val = phase[kw].rvs(random_state=rng_seed)
except AttributeError:
val = phase[kw]
seed_args[kw] = val
elif (phase[kw] == 'random') and (n_dim == 2):
np.random.seed(rng_seed)
seed_args['angle_deg'] = 360 * np.random.rand()
elif phase[kw] == 'random':
np.random.seed(rng_seed)
elems = np.random.normal(size=4)
mag = np.linalg.norm(elems)
elems /= mag
val = Quaternion(elems).rotation_matrix
seed_args[kw] = val
elif kw in ['rot_seq', 'rot_seq_deg', 'rot_seq_rad']:
seq = []
val = phase[kw]
if not isinstance(val, list):
val = [val]
for rotation in val:
rot_dict = {str(kw): rotation[kw] for kw in rotation}
ax = rot_dict.get('axis', 'x')
ang_dist = rot_dict.get('angle', 0)
try:
ang = ang_dist.rvs(random_state=rng_seed)
except AttributeError:
ang = ang_dist
seq.append((ax, ang))
seed_args[kw] = seq
else:
try:
val = phase[kw].rvs(random_state=rng_seed)
except AttributeError:
val = phase[kw]
seed_args[kw] = val
# Update the RNG seed
np.random.seed(rng_seed + kw_n)
rng_seeds[kw] = np.random.randint(max_int - kw_n)
kw_n += 1
# Add seed to list
seed = _seed.Seed.factory(seed_shape, **seed_args)
seeds.append(seed)
seed_vol += seed.volume
return cls(seeds)
